Air in-line sensor for ambulatory drug infusion pump

Abstract

An air in-line sensor for detecting air bubbles in a therapeutic solution flowing through a tube utilizes a unitary type sensor having a channel for receiving the tube. The channel has a tube loading section. A signal emitting member is positioned on one side of the tube and a signal receiving member is positioned on an opposite side of the tube. A first air baffle is positioned between the signal emitting and signal receiving members.

We claim:  
     
       1. An air in-line sensor for detecting air bubbles in a therapeutic solution flowing through a tube, the sensor comprising: 
       a channel for receiving the tube having a tube loading section;  
       a signal emitting member positioned on one side of the tube and a signal receiving member positioned on an opposite side of the tube; and,  
       a first air baffle positioned between the signal emitting member and the signal receiving member.  
     
     
       2. The sensor of  claim 1  further comprising a first lead-in section. 
     
     
       3. The sensor of  claim 2  wherein the first lead-in section comprises an upper portion of a first sidewall of the channel, the first lead-in section tapers upwardly and outwardly from an intermediate portion of the first sidewall to the upper portion of the first sidewall. 
     
     
       4. The sensor of  claim 1  wherein the first air baffle prevents an ultrasonic signal from traveling around the tube. 
     
     
       5. The sensor of  claim 1  further comprising a second air baffle. 
     
     
       6. The sensor of  claim 5  wherein the second air baffle is positioned between the signal emitting member and the signal receiving member. 
     
     
       7. The sensor of  claim 6  wherein the second air baffle prevents an ultrasonic signal from traveling around the tube. 
     
     
       8. The sensor of  claim 1  further comprising a second lead-in section positioned opposite the first lead-in section. 
     
     
       9. The sensor of  claim 8  wherein the second lead-in section comprises an upper portion of a second sidewall of the channel, the second lead-in section tapers upwardly and outwardly from an intermediate portion of the second sidewall to the upper portion of the second sidewall. 
     
     
       10. An air in-line sensor for detecting air bubbles in a therapeutic solution flowing through a tube, the sensor comprising: 
       a channel for receiving the tube having a first lead-in section, and a tube loading section;  
       a signal emitting member positioned on one side of the tube and a signal receiving member positioned on an opposite side of the tube; and,  
       a first air baffle positioned between the signal emitting member and the signal receiving member.  
     
     
       11. The sensor of  claim 10  wherein the first lead-in section comprises an upper portion of a first sidewall of the channel, the first lead-in section tapers upwardly and outwardly from an intermediate portion of the first sidewall to the upper portion of the first sidewall. 
     
     
       12. The sensor of  claim 10  wherein the first air baffle prevents an ultrasonic signal from traveling around the tube. 
     
     
       13. The sensor of  claim 10  further comprising a second air baffle. 
     
     
       14. The sensor of  claim 13  wherein the second air baffle is positioned between the signal emitting member and the signal receiving member. 
     
     
       15. The sensor of  claim 14  wherein the second air baffle prevents an ultrasonic signal from traveling around the tube. 
     
     
       16. The sensor of  claim 10  further comprising a second lead-in section positioned opposite the first lead-in section. 
     
     
       17. The sensor of  claim 16  wherein the second lead-in section comprises an upper portion of a second sidewall of the channel, the second lead-in section tapers upwardly and outwardly from an intermediate portion of the second sidewall to the upper portion of the second sidewall. 
     
     
       18. An air in-line sensor for detecting air bubbles in a therapeutic solution flowing through a tube, the sensor comprising: 
       a channel for receiving the tube having a tube loading section;  
       a first lead-in section comprising an upper portion of a first sidewall of the channel, the first lead-in section tapers upwardly and outwardly from an intermediate portion of the first sidewall to the upper portion of the first sidewall;  
       a second lead-in section comprising an upper portion of a second sidewall of the channel, the second lead-in section tapers upwardly and outwardly from an intermediate portion of the second sidewall to the upper portion of the second sidewall; and,  
       the tube loading section having a stationary section and a movable section hingedly connected to the stationary section, the movable section having a blade having a radius of curvature for positioning the tube in the tube loading section.  
     
     
       19. An air in-line sensor system for detecting air bubbles in a therapeutic solution flowing through a tube located in a pumping mechanism, the tube extending from a supply bag of the therapeutic solution to a patient through the system, the system comprising: 
       a channel for receiving the tube having a first lead-in section, and a tube loading section;  
       a signal emitting member positioned on one side of the tube and a signal receiving member positioned on an opposite side of the tube;  
       a first air baffle positioned between the signal emitting member and the signal receiving member; and,  
       the tube loader having a stationary section and a movable section hingedly connected to the stationary section, the movable section having a blade having a radius of curvature for positioning the tube in the tube loading section.  
     
     
       20. The system of  claim 19  wherein the pumping mechanism is selected from the group consisting of a peristaltic pump, a roller pump, an expulsor pump, a finger pump and a piston cassette pump. 
     
     
       21. The sensor of  claim 19  wherein the first lead-in section comprises an upper portion of a first sidewall of the channel, the first lead-in section tapers upwardly and outwardly from an intermediate portion of the first sidewall to the upper portion of the first sidewall. 
     
     
       22. The sensor of  claim 19  wherein the first air baffle prevents an ultrasonic signal from traveling around the tube. 
     
     
       23. The sensor of  claim 19  further comprising a second air baffle. 
     
     
       24. The sensor of  claim 23  wherein the second air baffle is positioned between the signal emitting member and the signal receiving member. 
     
     
       25. The sensor of  claim 24  wherein the second air baffle prevents an ultrasonic signal from traveling around the tube. 
     
     
       26. The sensor of  claim 19  further comprising a second lead-in section positioned opposite the first lead-in section. 
     
     
       27. The sensor of  claim 26  wherein the second lead-in section comprises an upper portion of a second sidewall of the channel, the second lead-in section tapers upwardly and outwardly from an intermediate portion of the second sidewall to the upper portion of the second sidewall. 
     
     
       28. An air in-line sensor for detecting air bubbles in a therapeutic solution flowing through a tube, the sensor comprising: 
       means for emitting an ultrasonic signal through the tube;  
       means for preventing the ultrasonic signal from traveling around the tube;  
       means for detecting the ultrasonic signal emitted through the tube;  
       means for measuring the strength of the ultrasonic signal emitted through the tube;  
       means for comparing the strength of the ultrasonic signal to a preset voltage value;  
       means for outputting a preset, maximum value for liquid and a preset, minimum value for air; and,  
       means for determining whether to sound an air in-line alarm.  
     
     
       29. The sensor of  claim 28  wherein the means for emitting is a transducer. 
     
     
       30. The sensor of  claim 28  wherein the means for preventing employs two air baffles positioned between a signal emitting member and a signal receiving member. 
     
     
       31. The sensor of  claim 28  wherein the means for detecting is a transducer. 
     
     
       32. The sensor of  claim 28  wherein the means for measuring employs an electrical circuit. 
     
     
       33. The sensor of  claim 28  wherein the means for comparing employs a voltage comparator. 
     
     
       34. An air in-line sensor for detecting air bubbles in a therapeutic solution flowing through a tube, the sensor comprising: 
       a channel for receiving the tube having a tube loading section;  
       a signal emitting member positioned on one side of the tube and a signal receiving member positioned on an opposite side of the tube;  
       a first lead-in section comprising an upper portion of a first sidewall of the channel, the first lead-in section tapers upwardly and outwardly from an intermediate portion of the first sidewall to the upper portion of the first sidewall; and,  
       a second lead-in section comprising an upper portion of a second sidewall of the channel, the second lead-in section tapers upwardly and outwardly from an intermediated portion of the second sidewall to the upper portion of the second sidewall.